什么是不能修改此节点的逻辑儿童在这个时候，因为一棵树的步行过程中是什么意思？ [英] What does Cannot modify the logical children for this node at this time because a tree walk is in progress mean?

查看：433
本文介绍了什么是不能修改此节点的逻辑儿童在这个时候，因为一棵树的步行过程中是什么意思？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我在后台工作线程完成方法中设置对象的DataContext的。出于某种原因，我得到一个错误说：

I am setting the DataContext of an object in the completed method of a background worker thread. For some reason, I get an error saying:

不能修改此节点的逻辑儿童在这个时候，因为一棵树的步行路程，在指向Chart1.DataContext进度= allDates线。

Cannot modify the logical children for this node at this time because a tree walk is in progress pointing to the Chart1.DataContext=allDates line.

这是什么树散步过程中是什么意思？我试着使用调度运行这样一套，以及和给出了同样的错误...任何想法？谷歌yeilds此错误消息什么。

What does a tree walk is in progress mean? I've tried doing this set using a Dispatcher operation as well and that gives the same error... Any ideas? Google yeilds nothing on this error message.

代码taht的造成，这是内部的微软的图表工具包...我不知道，如果我发现在他们的控件中的错误...

The code taht's causing this is internal to Microsoft's Charting toolkit... I wonder if I've found a bug in their control...

没有调度员：

 void bg_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        ArticlesPerTimePeriodResult result = (ArticlesPerTimePeriodResult)e.Result;
        lvArticles.ItemsSource = result.DatesOfArticles;


        Chart1.DataContext = result.AllDates;
    }

通过调度员：

 void bg_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        ArticlesPerTimePeriodResult result = (ArticlesPerTimePeriodResult)e.Result;
        lvArticles.ItemsSource = result.DatesOfArticles;

        Dispatcher.BeginInvoke((Action<List<KeyValuePair<DateTime,int>>>)(delegate(List<KeyValuePair<DateTime,int>> allDates)
        {
            Chart1.DataContext = allDates;
        }), result.AllDates);

        //Chart1.DataContext = result.AllDates;
    }



错误：

Error:

System.Reflection.TargetInvocationException was unhandled
  Message="Exception has been thrown by the target of an invocation."
  Source="mscorlib"
  StackTrace:
       at System.RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner)
       at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks)
       at System.Delegate.DynamicInvokeImpl(Object[] args)
       at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter)
       at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
       at System.Windows.Threading.DispatcherOperation.InvokeImpl()
       at System.Threading.ExecutionContext.runTryCode(Object userData)
       at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Windows.Threading.DispatcherOperation.Invoke()
       at System.Windows.Threading.Dispatcher.ProcessQueue()
       at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
       at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
       at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
       at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter)
       at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
       at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Boolean isSingleParameter)
       at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
       at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
       at System.Windows.Threading.Dispatcher.TranslateAndDispatchMessage(MSG& msg)
       at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
       at System.Windows.Application.RunInternal(Window window)
       at NewsCluesWpf.App.Main() in C:\SoftwareInstall\VSProjects\NewsClues\NewsCluesWpf\obj\Debug\App.g.cs:line 0
       at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
       at System.Runtime.Hosting.ApplicationActivator.CreateInstance(ActivationContext activationContext, String[] activationCustomData)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssemblyDebugInZone()
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: System.InvalidOperationException
       Message="Cannot modify the logical children for this node at this time because a tree walk is in progress."
       Source="PresentationFramework"
       StackTrace:
            at System.Windows.FrameworkElement.AddLogicalChild(Object child)
            at System.Windows.Controls.UIElementCollection.InsertInternal(Int32 index, UIElement element)
            at System.Windows.Controls.DataVisualization.ObservableCollectionListAdapter`1.<>c__DisplayClass1.<OnCollectionChanged>b__0(T item, Int32 index)
            at System.Windows.Controls.DataVisualization.EnumerableFunctions.ForEachWithIndex[T](IEnumerable`1 that, Action`2 action)
            at System.Windows.Controls.DataVisualization.ObservableCollectionListAdapter`1.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
            at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
            at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedAction action, Object item, Int32 index)
            at System.Collections.ObjectModel.ObservableCollection`1.InsertItem(Int32 index, T item)
            at System.Windows.Controls.DataVisualization.ReadOnlyObservableCollection`1.InsertItem(Int32 index, T item)
            at System.Collections.ObjectModel.Collection`1.Insert(Int32 index, T item)
            at System.Windows.Controls.DataVisualization.AggregatedObservableCollection`1.<>c__DisplayClass14.<>c__DisplayClass16.<ChildCollectionCollectionChanged>b__f(ReadOnlyObservableCollection`1 that)
            at System.Windows.Controls.DataVisualization.ReadOnlyObservableCollection`1.Mutate(Action`1 action)
            at System.Windows.Controls.DataVisualization.AggregatedObservableCollection`1.<>c__DisplayClass14.<ChildCollectionCollectionChanged>b__e(T item, Int32 index)
            at System.Windows.Controls.DataVisualization.EnumerableFunctions.ForEachWithIndex[T](IEnumerable`1 that, Action`2 action)
            at System.Windows.Controls.DataVisualization.AggregatedObservableCollection`1.ChildCollectionCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
            at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
            at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedAction action, Object item, Int32 index)
            at System.Collections.ObjectModel.ObservableCollection`1.InsertItem(Int32 index, T item)
            at System.Collections.ObjectModel.Collection`1.Add(T item)
            at System.Windows.Controls.DataVisualization.Charting.Chart.AddAxisToChartArea(Axis axis)
            at System.Windows.Controls.DataVisualization.Charting.Chart.ActualAxesCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
            at System.Collections.Specialized.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e)
            at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
            at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedAction action, Object item, Int32 index)
            at System.Collections.ObjectModel.ObservableCollection`1.InsertItem(Int32 index, T item)
            at System.Windows.Controls.DataVisualization.UniqueObservableCollection`1.InsertItem(Int32 index, T item)
            at System.Collections.ObjectModel.Collection`1.Add(T item)
            at System.Windows.Controls.DataVisualization.Charting.DataPointSeriesWithAxes.GetAxes(DataPoint firstDataPoint, Func`2 independentAxisPredicate, Func`1 independentAxisFactory, Func`2 dependentAxisPredicate, Func`1 dependentAxisFactory)
            at System.Windows.Controls.DataVisualization.Charting.AreaSeries.GetAxes(DataPoint firstDataPoint)
            at System.Windows.Controls.DataVisualization.Charting.DataPointSeriesWithAxes.GetAxes()
            at System.Windows.Controls.DataVisualization.Charting.DataPointSeriesWithAxes.OnDataPointsChanged(IList`1 newDataPoints, IList`1 oldDataPoints)
            at System.Windows.Controls.DataVisualization.Charting.DataPointSingleSeriesWithAxes.OnDataPointsChanged(IList`1 newDataPoints, IList`1 oldDataPoints)
            at System.Windows.Controls.DataVisualization.Charting.LineAreaBaseSeries`1.OnDataPointsChanged(IList`1 newDataPoints, IList`1 oldDataPoints)
            at System.Windows.Controls.DataVisualization.Charting.DataPointSeries.LoadDataPoints(IEnumerable newItems, IEnumerable oldItems)
            at System.Windows.Controls.DataVisualization.Charting.DataPointSeries.Refresh()
            at System.Windows.Controls.DataVisualization.Charting.DataPointSeries.OnItemsSourceChanged(IEnumerable oldValue, IEnumerable newValue)
            at System.Windows.Controls.DataVisualization.Charting.DataPointSeries.OnItemsSourceChanged(DependencyObject o, DependencyPropertyChangedEventArgs e)
            at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
            at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
            at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
            at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, OperationType operationType)
            at System.Windows.DependencyObject.InvalidateProperty(DependencyProperty dp)
            at System.Windows.Data.BindingExpression.Invalidate(Boolean isASubPropertyChange)
            at System.Windows.Data.BindingExpression.TransferValue(Object newValue, Boolean isASubPropertyChange)
            at System.Windows.Data.BindingExpression.Activate(Object item)
            at System.Windows.Data.BindingExpression.HandlePropertyInvalidation(DependencyObject d, DependencyPropertyChangedEventArgs args)
            at System.Windows.Data.BindingExpression.OnPropertyInvalidation(DependencyObject d, DependencyPropertyChangedEventArgs args)
            at System.Windows.DependentList.InvalidateDependents(DependencyObject source, DependencyPropertyChangedEventArgs sourceArgs)
            at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
            at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, OperationType operationType)
            at System.Windows.TreeWalkHelper.OnInheritablePropertyChanged(DependencyObject d, InheritablePropertyChangeInfo info)
            at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d)
            at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren)
            at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
            at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
            at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d)
            at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren)
            at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
            at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
            at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d)
            at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren)
            at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
            at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
            at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d)
            at System.Windows.DescendentsWalker`1.WalkLogicalChildren(FrameworkElement feParent, FrameworkContentElement fceParent, IEnumerator logicalChildren)
            at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
            at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
            at System.Windows.DescendentsWalker`1._VisitNode(DependencyObject d)
            at System.Windows.DescendentsWalker`1.WalkFrameworkElementLogicalThenVisualChildren(FrameworkElement feParent, Boolean hasLogicalChildren)
            at System.Windows.DescendentsWalker`1.IterateChildren(DependencyObject d)
            at System.Windows.DescendentsWalker`1.StartWalk(DependencyObject startNode, Boolean skipStartNode)
            at System.Windows.TreeWalkHelper.InvalidateOnInheritablePropertyChange(FrameworkElement fe, FrameworkContentElement fce, InheritablePropertyChangeInfo info, Boolean skipStartNode)
            at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
            at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
            at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, OperationType operationType)
            at System.Windows.DependencyObject.SetValueCommon(DependencyProperty dp, Object value, PropertyMetadata metadata, Boolean coerceWithDeferredReference, OperationType operationType, Boolean isInternal)
            at System.Windows.DependencyObject.SetValue(DependencyProperty dp, Object value)
            at System.Windows.FrameworkElement.set_DataContext(Object value)
            at NewsCluesWpf.ArticlesPerDay.<bg_RunWorkerCompleted>b__1(List`1 allDates) in C:\SoftwareInstall\VSProjects\NewsClues\NewsCluesWpf\ArticlesPerDay.xaml.cs:line 72
       InnerException:


推荐答案

玩弄更多的，我认为这是Silverlight图表工具包的bug。

After playing around more, I think this is a bug in the Silverlight charting toolkit.

下面的代码会导致一个可重复执行崩溃。

The following code causes a reproduceable crash. 

int runCount = 0;
        private void bindChart(string searchString)
        {
           List<KeyValuePair<DateTime, int>> dataEmpty = new List<KeyValuePair<DateTime, int>>();

            List<KeyValuePair<DateTime, int>> dataFilled = new List<KeyValuePair<DateTime, int>>();
            dataFilled.Add(new KeyValuePair<DateTime, int>(DateTime.Today, 1));
            if (runCount == 0)
            {
                Chart1.DataContext= dataEmpty;
            }
            else
            {
                Chart1.DataContext = dataFilled;
            }
            runCount++;

        }



XAML：

XAML:

<charting:Chart Grid.Row="0"
    Title="Title"
    LegendTitle="Legend" Name="Chart1" Grid.RowSpan="2">
            <charting:AreaSeries ItemsSource="{Binding}"

                                       DependentValuePath="Value"

                                       IndependentValuePath="Key"

                                       Background="Red" />


        </charting:Chart>

这将无法在第二次调用bindChart。

This will fail on the second call to bindChart.

这篇关于什么是不能修改此节点的逻辑儿童在这个时候，因为一棵树的步行过程中是什么意思？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！

查看全文
相关文章
C#/.NET最新文章
热门教程
热门工具
登录 关闭
扫码关注1秒登录
发送“验证码”获取 | 15天全站免登陆